Your original topic has been closed for some reason.
First find the image that you want on a website(it has to be already on the web). Right click on that image and go to properties. That will show the web address of that image: for example-
http://www.aviationpics.de/preview/jag1.jpg
In front of http insert [img] at the end of the address, insert [/img]
Hopefully you should now see the piccie